Patents by Inventor Wheeler Conrad Crawford

Wheeler Conrad Crawford has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6340559
    Abstract: Provided herein are developer solutions useful in producing semiconductor-based circuit elements or precursors thereof, which contain tris-(2-hydroxyethyl)methylammonium hydroxide. Developers according to the invention are either aqueous or alcoholic solutions of tris-(2-hydroxyethyl)methylammonium hydroxide which preferably further comprise a stabilizer. Through use of the compositions provided herein, greatly reduced levels of volatile amines are released during the developing process which lessens the burden on clean room atmosphere purification equipment owing to lessened airborne impurities.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: January 22, 2002
    Assignee: Huntsman Petrochemical Corporation
    Inventors: Wei-Yang Su, Stephen Lee Sjoberg, Wheeler Conrad Crawford
  • Patent number: 5646235
    Abstract: A method is provided for the preparation of tertiary polyamines by alkylating a polyamine having at least two primary amino groups without the use of excess solvent. More particularly, a tertiary amine is produced by reductively alkylating a polyamine with a carbonyl compound, such as formaldehyde, in a reaction zone while in the presence of a hydrogenation catalyst and hydrogen under reductive conditions. The carbonyl compound is continuously supplied to the reaction zone.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: July 8, 1997
    Assignee: Huntsman Petrochemical Corporation
    Inventors: Robert LeRoy Zimmerman, Wheeler Conrad Crawford, Rodney Frederick Lloyd